1. Field of the Invention
The present invention relates to methods for producing gas and hydrocarbons from fluid containing beds.
2. Description of the Prior Art
It is common knowledge that gas is produced from gas; condensed gas; condensed oil-and-gas- and gas-hydrated deposits. In addition to already formed gas deposits, significant gas resources are contained in aquifers, in soluted, dispersed or isolated in the lenses forms. Significant gas volumes in said forms are also contained in formerly developed deposits wherein gas production has been terminated due to water entering the wells.
The gas phase in the form of traps (lenses) can exist both in formations with an essential bed pressure and in depleted formations.
There are known a number of methods of producing gas from fluid-containing beds, providing pumping out the bed fluid. Thus, there is known a method of gas production, providing transportation of gas along with the bed fluid to the surface with subsequent gas separation (Reference Book on Gas Production, Moscow, Nedra, 1974, pp. 511-512).
There is known another method of increasing a recovery of natural gas from an aquifer, providing drilling of one or more wells in the region of an aquifer, reducing the pressure in the bed by pumping out a part of the bed fluid and extracting the released gas (U.S. Pat. No. 4,040,487). This design allows one to avoid gas separation on the earth surface.
There is also known a method of increasing a natural gas recovery from an aquifer having a trap, which differs from the previous one in that the wells are drilled around the trap to a point below the lower boundary thereof. Utilization in this method of a trap as an intermediate reservoir for gas accumulation, makes it possible to compensate a non-uniform removal of the gas from the bed (U.S. Pat. No. 4,116,276).
There is further known a utilization in the fluid hydrocarbon production of a stimulating and intensifying influence on the bed by means of elastic pressure waves generated by appropriate sources in a medium contacting the bed and/or directly in the bed.
In the known methods are utilized the low-amplitude elastic vibrations generated in a seismic frequency range from 0.1 to 500 Hz (U.S. Pat. No. 4,417,621) and pumping gas (CO.sub.2) to the bed. Also, there is used a pulse influence by electric discharge devices arranged in a well (U.S. Pat. No. 4,169,503; U.S. Pat. No. 5,004,050).
Moreover, the utilization of seismic vibrations stimulates gas flow through the bed.
There is known a method of producing gas from fluid containing beds having at least one gas trap, providing influencing the bed by means of elastic vibrations generated directly in the bed and/or in a medium contacting the bed by an oscillation source, and removal of the gas from the trap (PCT/RU 92/00025).
Said technical solution, combining influence on the fluid containing bed by means of elastic vibrations and accumulation of gas released at degassing a trap, gives a possibility to use on an industrial scale the flooded formations with low bed pressure and also provides extracting gas from gas containing aquifers.